When developing apps for Windows Phone 8, every developer needs to know how to create and manage the App Bar. The problem is you cannot use databindings and/or localization in App bar buttons and menu items, you also cannot bind the colors or enabled state or even use commands bound to the buttons.

Most apps I've seen uses tedious programmatic initialization in code, repetitive entering of same resource values, or even not localized App bar at all. But there is an easy solution - the AppBarUtils library.

With this library you can use databinding for all AppBar properties, use Commands, even use dynamic app bar content for currently selected pivot/panorama item or your own state like logged-in/logged-out user. Let's see, how to do it.

When I was recently developing one Windows 8 app that supports the "Share Contract", I've experienced strange problems when the sharing suddenly stopped working not just in my app, but for all apps launched from my account. I had to log-off and log- in to make it work again. I thought it was just some kind of temporary issue until I discovered that it cause my app. After hour of testing I've pinpointed the actual issue and came to conclusion:

Any Windows 8 app running in sandbox can break the Share Contract for ALL other Windows 8 apps running under the same account, until the user logs off and on again!

Here's the detailed explanation how to do it, it's quite simple, nothing tricky.